JPH0792078A - Adhesive-agent testing device - Google Patents

Abstract

PURPOSE: To test the strength of an adhesive by providing a movable carriage nounting a substrate, anvil member, and a devices of applying the adhesive, pressing the carriage and the anvil, and measuring the separating force. CONSTITUTION: A substrate 4 is fixed to a carriage 2 with a double-face type adhesive. The carriage 2 is provided with a threaded internal cavity engaged with a threaded rod 6 which can be driven. A proper adhesive is layed in a magazine 34 and a driver to the rod 36 is connected, and thereby the carriage is moved rightward. The reversal of the carriage 2 occurs when a roller reaches a gap 24, and the substrate 4 receives the adhesive having patterns corresponding to the kinds of wheels. The carriage 2 is stopped above an anvil and presses the same against the carriage 2. The pressure is then released by a piston. The driver raises a cam 54 and actuates a doward force onto a steel beam 48. The cam 54 raises a beam 50 while a distrotion meter measures the maximum bending of the beam 48 by which the layer of adhesive is destroyed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to an apparatus for testing adhesives, and more particularly to an apparatus for testing the strength of an adhesive layer formed by an adhesive between substrates.

[0002]

BACKGROUND OF THE INVENTION In packing machines, such as machines for making or packaging packets of cigarettes, the conditions under which seals are typically made are constrained by mechanical operation. A step is required to secure the surfaces of the (eg, packet flaps) together. For example, in such devices, the time the surfaces are pressed together (or with the application of heat) to create an adhesive layer is such that the bond can be reliably maintained when the pressure on these surfaces is released. Is clearly desirable.
It is an object of the present invention to provide a device that is capable of simulating various conditions known in the manufacturing machine in which the adhesive can be used and testing the strength of the adhesive layer made in such conditions. It is the purpose of the invention. The measured adhesive strength is then compared to the strength considered necessary for satisfactory sealing of the surface during use.

[0003]

According to the present invention, an adhesive testing device includes a movable carriage to which a substrate can be attached, an anvil member to which another substrate can be attached, and an adhesive. A device for applying to the substrate on the carriage, a device for moving the carriage to a position opposite the anvil, and a pressure on the carriage and anvil to bring the substrate and the intervening adhesive together under pressure. And a device for subsequently separating the anvil and the carriage, and a device for measuring the force required to separate the anvil and the carriage to obtain a strength measurement between the substrates. including.

Preferably, the adhesive testing device is a device for controlling the time between the application of adhesive and the mating of the substrates together between the carriage and anvil, the time the carriage and anvil are pressed together. And / or a device for controlling the time between the release of pressure between the carriage and anvil and the subsequent separation of the carriage and anvil. In addition, preferably the pressure applied between the anvil and the carriage is controllable. Also, preferably the anvil can be heated to a controlled temperature.

In addition, the adhesive application device preferably includes a device for varying the amount, thickness, pattern, and / or temperature of the adhesive applied to the substrate.

An apparatus for separating an anvil and a carriage may have a separating force that is substantially perpendicular to the substrate, or a separating force that is substantially parallel to the substrate, or any other direction that seeks to separate the substrate. Separation power of can be imposed.

In a preferred configuration in which the separating force is substantially perpendicular to the substrate, the anvil comprises a strain gauge that produces a measure of the force required to separate the adhesive layer between the substrates. Mounted on a horizontal beam. The beam is pivoted and can be subjected to the action of a moment, for example provided by a rotating cam, which tends to separate the anvil from the carriage. If the separating force is substantially parallel to the substrate so that the shear strength of the adhesive layer is tested, the anvil includes a rotating member constrained by an elastic device, the deflection of which produces a shear strength measurement. provide. Thus, after the adhesive layer is formed between the substrates, a substantially tangential force can be applied to the carriage, which force is resisted by the elastic device as long as the adhesive layer is retained.

The device for pressing the carriage and the anvil together may include a device for pressing the anvil toward the carriage, such as an air clamp, the anvil being conveniently located substantially beneath the carriage. It
The carriage can move along a substantially horizontal path between the adhesive applicator and a position opposite the anvil.

In another preferred arrangement, the carriage is capable of moving past the adhesive applicator along a substantially horizontal path whereby the substrate is moved while the carriage is moving along said path. Receive the adhesive. By configuring the adhesive to be applied to a moving substrate,
The adhesive application could simulate many types of machine-appearing applications, and the speed of movement of the carriage could be varied while the adhesive was applied. If the adhesive applicator includes a driven member (eg, applicator wheel), the carriage and driven member can be synchronized,
Thereby they have the same speed during application of the adhesive.
For example, a device can be provided to heat the adhesive to a desired temperature so that a hot melt adhesive can be used.

In another preferred arrangement in which the carriage can move along a substantially horizontal path, the carriage includes a surface carrying a substrate, the surface being at a topmost position in an initial position on the path along which the carriage moves. But then flipped so that the surface is at the bottom when it is facing the anvil. By arranging that the surface of the carriage to which the substrate is attached is first in the uppermost position, the fixing of the substrate to the surface (which can be done by a double-sided adhesive tape) is facilitated. The adhesive may be applied to the substrate while the substrate is facing up and / or while it is facing down. For this reason, the adhesive can conveniently be fed downwards onto the substrate by spraying or jetting in a first part of the path of the carriage, and the carriage is inverted in the second part of said path. By the way, for example, it can be applied upwards by means of an applicator wheel having a lower periphery in the adhesive reservoir.

The movable carriage has a body having a surface for carrying a substrate, a threaded bore configured to cooperate with a threaded drive shaft, and a track having first and second portions. A first and a second longitudinally offset lateral guide member configured to cooperate with the carriage along the first and second portions, the carriage being at the top and bottom of the surface, respectively. And (i.e., the carriage is in a mutually inverted position in the first and second portions) for reversible movement, wherein the first and second portions of the track are about the axis of the axis. The carriage is separated by at least one gap allowing passage of the guide member during 180 ° reversal, said reversal being obtained by transmission of rotation to the carriage by said axis, rotation of the carriage at other times being said trajectory and said guide It is resisted by at least one of the engagement of wood.

It will be appreciated that the substrate fixed to the carriage and anvil is chosen for the purpose of being tested with the adhesive. In other words, it will be appreciated that the substrate material can have a significant effect on the performance of the adhesive. The commercially available double-sided adhesive tape used to secure the substrate to the carriage and anvil has a sufficiently higher bond strength than the adhesive typically used in packing machines,
Its use does not affect the results obtained by the device.

The invention will be further described by way of example only with reference to the accompanying schematic drawings.

[0014]

1 and 2 show an adhesion test apparatus including a carriage 2 for supporting a substrate 4 configured to receive a coating of adhesive. The substrate 4 can consist of a strip of card, plank, paper, film, foil or other relatively flat material on which it is desired to test the adhesive. The substrate 4 can be fixed to the carriage 2 with a double-sided adhesive tape.

The carriage 2 has an internal threaded bore which is engaged with a drivable threaded rod 6. Rotation of the rod 6 by the pulley 8 and the driven belt 10 causes the carriage 2 to rotate on the rod 6.
Along with its initial position (shown in FIG. 1) and between the adhesive application position 12 and the adhesive test position 14 acts to carry it reversibly.

The carriage 2 is a lateral roller 1 which is unevenly distributed.
6, 18 which are in engagement with the stationary lower rails 20, 22 respectively in the position shown in FIG.
On the upstream side of the adhesive application position 12, there is a short gap 24 between the lower rails 20 and 22, and beyond the gap, the upper rail 2
8, 30 are each spaced above the lower rail by a distance which is slightly larger than the diameter of the rollers 16, 18. Therefore, on the downstream side of the gaps 24, 26, each rail 2
0, 22 and 22, 30 form the tracks of the rollers 16, 18.

Rotation of the shaft 6 in the counterclockwise direction (as seen from the pulley 8) advances the carriage 2 to the right (as seen in FIG. 1) and the tendency of the carriage to rotate about the shaft 6 is the rail 2
Resisted by roller 16 engaging zero. However, when the roller 16 reaches the gap 24, the carriage 2
Makes a 180 ° rotation about the axis of the shaft 6 and any further rotation is blocked by the engagement of the roller 18 with the rail 20. Subsequent advancement of the carriage 2 passes the roller 16 into the track formed between the rails 22 and 30, which prevents the carriage 2 from further rotational movement when the roller 18 reaches the gap 24.

Therefore, as shown in FIG. 2, the substrate 4 is underside when the carriage 2 reaches the adhesive applicator position 12. The adhesive applicator consists of an applicator wheel 32 rotatably supported in a magazine 34, the lower part of the magazine forming an adhesive reservoir. The magazine 34 is fixed to the structure of the device by means of threaded bolts incorporating a handle 36 and comprises height adjusting screws 38, by means of which the height of the wheel 32 with respect to the carriage 2 can be adjusted and furthermore on the wheel 32. Screw adjusting device 40 for scraper 42 for controlling the thickness of the adhesive film
including. Belt drive 44 is provided to rotate applicator wheel 32.

Adhesive test position 1 also shown in FIGS. 3 and 4.
At 4, the carriage 2 comes to rest above an anvil 46 which carries on its upper surface another substrate of the material whose adhesive is intended to be tested. The substrate on anvil 46 can be (but need not be) of a material similar to that of substrate 4, and can likewise be secured to the anvil by double-sided adhesive tape. The anvil 46 is connected to one end of a spring steel beam 48, the other end of which is bolted to a rigid beam 50. The composite beams 48, 50 are pivotally mounted at 52 and the beam 50 is engaged by a rotatable cam 54 which tends to raise it. Strain gauge 60
Mounted on spring steel beam 48.

An air clamp 56 having a piston 58 is provided directly beneath the anvil 46. Piston 58
Engages anvil 46 and is movable to apply a variable upward pressure on the anvil.

During operation, the carriage 2 is initially stationary in the position shown in FIG. A suitable substrate 4 is applied to the carriage 2 and also to the anvil 46 and a suitable adhesive is placed in the magazine 34. A drive to the rod 36 is then coupled to drive the carriage 2 to typically 25 meters /
Move to the right at the speed of a minute. The reversal of the carriage 2 occurs when the rollers 16 reach the gap 24, after which the carriage passes over the applicator wheel 32, which is driven by the pulley drive 44 at a peripheral speed corresponding to the linear speed of the carriage 2. To be done. Therefore, the base 4
Receives a pattern of adhesive depending on the type of wheel 32. Then, the carriage 2 comes to rest above the anvil 46. Predetermined variable time (“open” time)
After that, the air clamp 56 moves the piston 58 to the anvil 46.
Is actuated to move against the carriage and press the anvil against the carriage, thereby applying pressure to the two substrates and the sandwiched adhesive. The pressure applied to the anvil 46 can be changed by changing the air pressure supplied to the air clamp 56, which air pressure is applied for a predetermined variable time (“close” time). afterwards,
The pressure applied by piston 58 is released, and after a predetermined variable time ("pause" time), cam 54
The drive to the cam is actuated to rotate the cam slowly (about 5 rpm), which raises the beam 50, thereby applying a downward force onto the spring steel beam 48, which force is transmitted to the anvil 46 and It is resisted by the adhesive layer between the substrate on the anvil and the substrate on the carriage 2. The cam 54 can produce a 5 mm lift of the beam 50, which is typically a 2.5 mm thick spring steel beam 48.
Creates an opening force that can destroy the adhesive layer between the substrates. The strain gauge 60 measures the maximum deflection of the beam 48 just before the adhesive layer breaks.

The "open", "closed", and "pause" times mentioned above can be predetermined by the control circuitry (including, for example, a microprocessor) and are typically 0.1 seconds. It can be between 99.9 seconds.
The pressure that can be applied to the anvil 46 by the piston 58 is in the range of 0-4 kg / cm ² (0-55 psi), but typically the pressure applied is in the lower part of this range, for example 0. 0.07 to 0.35 kg / cm ² (1 to 5 ps
i). The strain gauge 60 is connected through suitable circuitry (preferably including an analog-to-digital converter and again a microprocessor) to provide an indication of the force (or pressure) required to break the adhesive layer. You can In order to provide such an indication (eg of weight) in a conventional unit, the composite beam 48, 50 and strain gauge 60 configurations are first calibrated by spring gauges or applied weights.

Other parameters that can be varied are the amount, thickness and type of adhesive along with the adhesive application method and pattern. The adhesive can be applied at ambient temperature or at elevated temperature (eg for hot melt adhesives). To this end, magazine 34 may include heating elements and temperature sensors, which are conveniently connected by leads (not shown) to socket 62 (FIG. 2) for control and indication of adhesive temperature. To be done.

The anvil 46 includes a heating element to raise its temperature, which can be raised to the desired value and preferably displayed on the device.

5 to 8 show the carriage 2, the roller 16,
18 and rails 20, 22, 28 and 30 are shown, without much of the additional portion shown in FIGS.

9-11 show the adhesive applicator wheel 32 and related parts in more detail than FIGS. 1 and 2.

FIG. 12 shows the area of the device in which the carriage 2 is arranged with the base body at the top, namely the rails 20, 22.
Of the spray or jet head 66 for applying adhesive to the substrate 4 upstream of the gaps 24, 26 and at or near the position of the carriage shown in FIG.
Shown is an overhead adhesive spray or jet unit 64 with a.
Therefore, if the device incorporates a spraying unit 64,
A controlled amount of adhesive can be applied to the substrate 4 by the spraying unit 64 and / or by the applicator wheel 32.

It will be appreciated that the carriage 2 can be stopped in the correct position above the anvil 46 by means of suitable optical sensors which detect its position and stop the drive to the threaded shaft 6. After the adhesive bond strength test is complete, drive to shaft 6 is resumed in the opposite direction, returning carriage 2 to the position shown in FIG. During that reverse movement, the adhesive need not be applied to the substrate by the wheel 32. The carriage 2 is automatically turned over again, ie when the roller 16 reaches the gap 26 the substrate 4 is again in the uppermost position. The drive to the shaft 6 is stopped when the carriage 2 reaches the position shown in FIG. 1 (as detected by a suitable photosensor).

The apparatus described thus far provides a measure of bond strength in a direction substantially perpendicular to the bonded substrate. For some adhesives and / or the use of adhesives, the measurement of shear strength, i.e. in a direction substantially parallel to the bonded substrate, is suitable. 13 and 14 show an alternative adhesive test position 114 in which the anvil 46 is replaced by an anvil roller 146 attached to the yoke 148. The anvil roller 146 (which can be heated) carries the substrate that is pressed against the adhesive-bearing substrate on the underside of the carriage 2. When it is required to test the shear strength of the adhesive layer, the drive to the threaded shaft 6 is started again (preferably in the opposite direction). For this reason, the rotational force is due to the adhesive layer between the substrates, and thus the anvil roller 14
6 is transmitted. This rotation is resisted by the internal coil spring. Spring deflection corresponding to roller rotation is measured by a strain gauge. Maximum deflection occurs at the maximum shear strength of the adhesive layer (ie, when the adhesive layer between the substrates fails). The strength of the internal coil spring in the anvil roller 146 is critical for forces that tend to break the adhesive layer due to the separation of the curved surface of the anvil roller from the flat surface of the carriage when the anvil roller is rotating. It will be appreciated that, in order to avoid undesired effects, the rotation of the roller before breaking the adhesive layer is chosen to be relatively small. Similarly,
In order to avoid inaccurate readings, the pressure is released from the air clamp 56 during the test so that the measurement of the adhesive layer shear strength is not blocked by the frictional action of the pressure applied between the anvil roller 146 and the carriage 2. It Instead of measuring the deflection of the internal spring, the deflection of the roller itself (or the shaft connected to it) can be measured directly,
Or, for example, the deflection of an external spring coupled to the shaft to which the roller is attached and resisting rotation of the shaft can be measured.

Adhesion test location 114 can replace location 14 in the device and is otherwise similar to that of FIG.

[Brief description of drawings]

FIG. 1 is a plan view of an adhesive testing device according to a preferred embodiment of the present invention.

2 is a side view of the device of FIG.

FIG. 3 is a view in the direction of arrow III in FIG.

4 is a view in the direction of arrow IV in FIG.

5 is a plan view of the carriage and track assembly of the apparatus of FIG.

6 is a side view of the assembly of FIG.

7 is an end view in the direction of arrow VII in FIG.

8 is an end view in the direction of arrow VIII in FIG.

9 is a plan view of the adhesive applicator of the apparatus of FIG.

FIG. 10 is a side view of the applicator of FIG.

11 is a view in the direction of arrow XI in FIG. 9.

FIG. 12 is a cross-sectional view of a modified adhesive testing device that incorporates two adhesive applicators.

FIG. 13 is an end view of a portion of another modified adhesive applicator device.

FIG. 14 is a view in the direction of arrow XIV in FIG.

[Explanation of symbols]

 2 Carriage 4 Substrate 6 Rod 12 Adhesive Application Position 14 Adhesive Test Position 16 Roller 18 Roller 20 Rail 22 Rail 24 Gap 26 Gap 28 Rail 30 Rail 32 Applicator Wheel 42 Scraper 46 Anvil 48 Spring Steel Beam 50 Rigid Beam 54 Cam 56 Air Clamp 58 Piston 60 Strain Gage 66 Spray or Jet Head 114 Adhesive Test Position 146 Anvil Roller

Claims (23)

[Claims] 1. A movable carriage (2) to which a substrate (4) can be mounted, an anvil member (46; 146) to which another substrate can be mounted, and a substrate on which the adhesive is movable. Device for applying to (3
2; 66), a device (6) for moving the carriage to a position (14; 114) opposite the anvil, and the carriage and anvil together to bring the substrate and the intervening adhesive together under pressure. Device for pressing (5
6, 58), a device for separating the anvil and the carriage thereafter (6; 48-54), necessary for separating the anvil and the carriage so as to obtain a measure of the strength of the adhesive layer between the substrates. An adhesive testing device including a device (60) for measuring the applied force. 2. Anvil (46) and carriage (2).
Adhesive testing device according to claim 1, wherein the device (48-54) for separating the substrate imposes a separating force comprising at least a substantial component perpendicular to the substrate. 3. The anvil (46) is mounted on a beam (48, 50) carrying a strain gauge (60) which produces a measurement of the force required to separate the adhesive layer between the substrates. The adhesive testing device according to claim 2. 4. Adhesive testing device according to claim 3, wherein the beam (48, 50) is pivoted and the separating device comprises a device (54) for pivoting the beam. 5. Adhesive test according to claim 1, wherein the device (6) for separating the anvil (146) and the carriage (2) imposes a separating force comprising at least a substantial component parallel to the substrate. apparatus. 6. The adhesive testing device of claim 5, wherein the anvil includes a rotating member (146) constrained by an elastic device, the flexure of the elastic device providing a measurement of the shear strength of the adhesive layer. 7. Adhesive applicator (32; 66) is configured to apply adhesive to a substrate (4) on a movable carriage (2) while the carriage is moving. The adhesive testing device described in any one of 1 to 6. 8. The adhesive testing device according to claim 7, wherein the adhesive applying device comprises a driven member (32) which can be moved at the same speed as the carriage (2) during adhesive applying. 9. The moving device (6) according to claim 7 or 8, wherein the moving device (6) comprises a device for changing the speed at which the carriage (2) is moved past the adhesive application position (12; 66). Adhesive testing equipment. 10. A device defining a path for a carriage (2) extending through the adhesive application location (12; 66) and to the location (14; 114) opposite the anvil (46; 146). Adhesive testing device according to any one of claims 1 to 9, including 20, 22, 28, 30). 11. Device (16, 18, 24, 2) for reversing a carriage (2) during its movement along said path.
The adhesive testing device according to claim 10, including 6). 12. The carriage (2) comprises a surface carrying a substrate (4) and is capable of moving along a substantially horizontal path, said surface being on a first part of said horizontal path. 12. The adhesive testing device of claim 11, wherein the adhesive testing device is at the top and at the bottom on the second portion of the path, the second portion including the location (14; 114) opposite the anvil. 13. The adhesive testing device of claim 12, wherein the device for applying adhesive comprises a spraying device (66) proximate the first portion of the path. 14. An adhesive applicator according to claim 12 or 13, comprising an applicator wheel (32) engaging a substrate (4) on the carriage (2) in the second part of the path. Adhesive testing equipment. 15. The movable carriage (2) has a body having a surface for carrying a substrate (4), and a threaded bore configured to cooperate with a threaded drive shaft (6). A trajectory having first and second parts (20, 22, 28, 3
0) and first and second longitudinally offset lateral guide members (16, 18) configured to cooperate,
Adhesive as claimed in any one of the preceding claims, wherein the carriage along the first and second portions is capable of reversibly moving to the top and bottom of the surface, respectively. Test equipment. 16. The first and second parts of a track (20,22,28,30) are said guide members during a 180 ° reversal of the carriage (2) about the axis of said axis (6). Separated by at least one gap (24,26) allowing passage of one of (16,18), said inversion being obtained by transmission of rotation to said carriage by said axis, rotation of carriage at another time being said track 16. The adhesive testing device of claim 15, resisted by engagement of at least one of said guide members with. 17. A device for controlling the time between the application of adhesive and the mating of the substrates between the carriage (2) and the anvil (46; 146).
16. The adhesive testing device according to any one of 1 to 16. 18. A carriage (2) and an anvil (4)
Adhesive testing device according to any one of claims 1 to 17 including a device for controlling the time that 6; 146) is pressed together. 19. A carriage (2) and an anvil (4)
Adhesive testing device according to any one of claims 1 to 18, including a device for controlling the time between the release of pressure during 6; 146) and the subsequent separation of the anvil and the anvil. 20. Carriage (2) and anvil (4)
6; 146) for pressing together (56, 5)
20. 8) is configured to apply a controllable variable pressure between the anvil and the carriage.
The adhesive testing device described in any one of 1. 21. A device for heating an anvil (46; 146) to a controlled temperature, comprising:
The adhesive testing device described in any one of 1. 22. The adhesive applicator device (32) is configured to transfer adhesive from an adhesive source (34) to a substrate and includes a device for controlling the temperature of the adhesive in the source. The adhesive testing device described in any one of 1 to 21. 23. The adhesive application device (32; 66) is a device (4) for varying the amount of adhesive applied to the substrate.
The adhesive testing device according to any one of claims 1 to 22, including 2).